1. Field of the Invention
The present invention relates to a mercury selective fluorescent chemosensor for selectively detecting mercury ions (Hg2+) by the compound represented by the formula 1. More specifically, the present invention provides a novel fluorescent sensitive compound prepared by introducing two aminopyrene subunits as a fluorescent sensitive moiety into a binding site of the compound represented by the formula 1, and provides a mercury selective fluorescent sensitive chemosensor for selectively detecting mercury ions (Hg2+).
2. Background of the Prior Art
To develop a selective and sensitive chemosensor for the chemically or physiologically significant ionic substances, various studies have been carried out.
As an example of such studies, a method for observing optical and electrochemical chemosensing characteristics for heavy metal ions such as lead(Pb2+) and cadmium(Cd2+) ((a) Takahashi, Y.; Kasai, H.; Nakanishi, H.; Suzuki, T. M. Angew. Chem., Int. Ed. 2006, 45, 913., (b) Oehme, I.; Wolfbeis, O. S. Mikrochim. Acta 1997, 126, 177, (c) Bonfil, Y.; Brand, M.; Kirowa-Eisner, E. Anal. Chim. Acta 2002, 464, 99) is known in the art. Also, a study using selective fluorescent chemosensing characteristics for alkali metal ions and alkaline earth metal ions ((a) Kollmannsberger, M.; Rurack, K.; Resch-Genger, U; Rettig, W; Daub, J. Chem. Phys. Lett. 2000, 329, 363. (b) Rurack, K; Sczepan, M.; Spieles, M.; Resch-Genger, U.; Rettig, W. Chem. Phys. Lett. 2000, 320, 87) and a study using selective fluorescent chemosensing characteristics for copper ion (Cu2+) (Dujols, V.; Ford, F.; Czarnik, A. W. J. Am. Chem. Soc. 1997, 119, 7386) were reported in the art.
In particular, mercury ions are well known for their toxicity in environmental field, and accordingly a research and development of detection sensor which is selective and sensitive for mercury ions (Hg2+) has been proceeded persistently. As an example, a method for detecting mercury ions (Hg2+) by observing selective fluorescence change with ratiometry method (Elizabeth M. Nolan, Stephen J. Lippard. J. Materials. Chemistry. 2005, 15, 2778) is known in the art. However, although it was reported that the method has selectivity for mercury ions (Hg2+), there are the following disadvantages: the method exhibits only weak ratiometry behavior of about four-fold, the method of preparing the compound is very complicated, and the method is severely affected by nickel and copper ions.
Accordingly, the prior chemosensor having selective fluorescent sensitive characteristics for mercury ions (Hg2+) should satisfy the following conditions: firstly, the chemosensor should not be affected by other metals in comparing with a target metal; second, the chemosensor should be able to respond even at a sufficiently low concentration; and third, the chemosensor should work even in a solution containing high water composition.
We have been persistently studying to develop a chemosensor having selective fluorescent signaling characteristics for mercury ions (Hg2+). As a result, we produced a novel fluorescent sensitive compound by introducing two aminopyrene functions as a fluorescence sensitive moiety into a binding site of the compounds represented by the formula 1. The changes in fluorescence of the compounds represented by the formula 1 were analyzed by ratiometric approach using monomer and excimer emissions of the pyrene fluorophore to selectively signal the concentration of mercury ions (Hg2+). In the case of detection of mercury ions (Hg2+) with the fluorescent sensitive compound of the present invention, a mercury selective fluorescent chemosensor provided by the present invention is not affected by other metal ions; is sensitive at a lower concentration; and can detect mercury ions in micromolar concentration even in a solution including an excess of water.